1. The Field of the Invention
The present invention relates to devices for coupling two or more bodies of sterile fluids in fluid communication. More specifically, the present invention relates to automated and semi-automated manners of conveniently and efficiently coupling bodies of sterile fluids in fluid communication within a sterile environment.
2. The Relevant Technology
Within the medical, biological, and pharmaceutical industries, the need frequently arises to couple bodies of sterile fluids in fluid communication with each other. In one instance, blood banks and hospitals must often transfer blood, plasma, and other biological fluids between different holders or containers. In a further example, pharmaceutical and research facilities often grow cell cultures within vats or sealed containers. Some manner of accessing to the materials being grown must be provided in order to supply nutrients to the materials, emit waste from the materials, and harvest the materials.
One type of container within which such products are frequently contained is a vinyl or PVC bag. Such bags can be sterilized quite easily by heating the bag at high temperatures or by radiation treatment of the bag. Connections between such containers is frequently made by plastic tubing, which is also typically formed of vinyl, PVC, and other types of synthetic materials. The tubing is also typically sterilized in advance using one of the described methods.
One difficulty arises due to the fact that different containers of fluids such as those mentioned above must be frequently disconnected and reconnected. For instance, in the growth of cell cultures, the cells may be nourished with a serum taken from blood products in which the platelets have been spun out. The serum containers are periodically exhausted and must be exchanged. The exchange of containers must be conducted while maintaining a completely sterile environment. Contamination of the containers can potentially render the contents worthless, and in only a single case, can cause the loss of hundreds of thousands of dollars.
Several manners of coupling such bodies of fluids exist in the prior art. In one example, the sterile fluids are contained in plastic containers. Plastic connectors are used to connect plastic tubing segments emanating from ports in the plastic containers. The tubing segments and plastic connectors are sterilized and kept in sealed paper or plastic bags until use. Nevertheless, making the connections between the tubing segments generally requires human contact. Making such connections requires the expense and inconvenience of maintaining elaborate sterile clean rooms, and any failure to maintain sterility of the process may result in contamination of the sterile fluids.
Semi-enclosed sterile environments have been used in the prior art for making such connections with some success. For example, a laminar flow hood has been used to create a sterile environment for sterilely joining tubing segments. Nevertheless, substantial human contact is still required in the process, and contaminants can be transferred from the operator""s hands to the interior of the tubing segments during the process.
A further prior art method currently used for coupling bodies of sterile fluids involves directly bonding the tubing segments together. Under this method, the sterile fluids are located within plastic containers and synthetic tubing segments are bonded to or otherwise connected to the plastic containers. The tubing segments are clamped shut and the edges of the tubing segments are heated until partially melted. The distal tips of the tubing segments are then aligned and held together until the heated plastic of the tubing segments bonds together.
This method of bonding tubing segments while successful to a degree, nevertheless still has its drawbacks. Human contact and its generally unavoidable consequences is still required. Additionally, the process is not carried out in a closed or otherwise sterile environment. Thus, contamination can still occur.
A similar method of joining synthetic tubing segments involves the use of a thin wafer. The wafer is heated by electricity through internal resistance. The wafer is then used to cut the tubing segments. After the tubing segments are cut, the wafer is then used to heat the ends of the tubing segments. The ends of the tubing segments are pinched closed with clamps during the process to avoid contamination and to provide sufficient pressure against the wafer during the heating process. Once heated, the pinched-off tubing segments are held together while the melted synthetic material cools to join the tubing segments. The tubing segments are then unpinched.
Drawbacks with this technique include the fact that the tubing may remain deformed and seal shut during the process. Additionally, due to heating and electricity constraints, only very small, low capacity, tubing is used, such as xe2x85x9 inch I.D. (inside diameter) tubing. This small diameter tubing is often sufficient for purposes such as use in the blood bank industry, but is insufficient for many other purposes. Additionally, this technique is generally not conducted in a sterile environment, and may yet be susceptible to contamination. Furthermore, the technique is difficult and awkward at best when dealing with tubing segments which are filled with fluid during the sealing of the tubing segments together.
Accordingly, a need exists for an improved manner of coupling bodies of sterile fluids in fluid communication. More specifically, such a manner is needed which overcomes the shortcomings of the prior art as described above.
The present invention solves many or all of the foregoing problems by providing an apparatus and method for joining first and second tubing segments together in sterile fluid communication to enable sterile fluid coupling between two bodies of sterile fluids through the first and second tubing segments. In one embodiment, the apparatus comprises an at least partial enclosure having an interior and is adapted to maintain a sterile environment within at least a substantial portion of the interior.
The apparatus also preferably comprises a tubing clamp adapted to receive the first and second tubing segments therein and mounted to be positionable within the enclosure. Additionally, the apparatus also preferably comprises a heating plate at least partially located within the enclosure. Preferably, the heating plate is provided with one or more heatable surfaces for concurrently heating the first and second tubing segments.
In one embodiment, the heating plate is adapted to sever distal ends of the first and second tubing segments. In an alternative embodiment, the apparatus comprises a cutting blade positionable within the interior to sever distal ends of the first and second tubing segments.
The tubing segments are in one embodiment substantially annular in cross-sectional shape. In this embodiment, the tubing clamp comprises a substantially annular opening adapted to receive the tubing segments without substantially deforming the tubing segments.
A heat source may also be provided, and is preferably connected to and provides heat to the heating device. In one embodiment, the heating plate comprises a hollow disk and the heat source comprises a hot air blower adapted to blow heated air into an interior of the hollow disk. In one embodiment, the cutting surface is also heated by the heat source.
The interior may comprise a heated aseptic environment for maintaining sterility of the tubing segments within the interior. The aseptic environment is preferably maintained by heat from the heat source. The clamps may be at least partially automated, and the clamps may be dynamically mounted upon a track adapted to guide the clamps into and out of the enclosure.
A method of the present invention may involve sterilely coupling first and second fluid bodies in fluid communication. In one embodiment, the method comprises providing the first and second fluid bodies and providing first and second tubing segments, the first tubing segment in fluid communication with the first fluid body and the second tubing segment in fluid communication with the second fluid body.
The method in one embodiment also comprises clamping distal ends of the first and second tubing segments into a selected position relative to an at least partial enclosure having an interior while maintaining a sterile environment within at least a substantial portion of the interior. A subsequent step preferably comprises heating the distal ends of the first and second tubing segments while within the enclosure.
The method also preferably comprises bringing the distal ends of the first and second tubing segments into contact with each other and allowing the distal ends to cool such that the first and second tubing segments bond to each other with a continuous lumen passing through the distal ends. The method may also comprise severing distal ends of the first and second tubing segments while the first and second tubing segments are within the enclosure.
In one embodiment, the first and second tubing segments are automatically transported into the interior once clamped in place for severing and heating, and then automatically transported out of the interior for bonding together. The tubing segments may also be automatically placed against the heating plate, and automatically placed in an adjoining position for bonding together.